Heavy duty quill assembly for a lawn mower

Abstract

A quill assembly for transmitting power from a belt drive to a lawn mower blade has a jackshaft positioned within a central bore of a housing. A blade adapter is recessed into the bottom of the housing to form a bearing seal and position the blade. A pulley adapter is positioned against the top of the housing and has a center section surrounded by a resilient outer section. The outer section of the pulley adapter includes a lip that fits into a groove formed in the outside of the housing to seal the housing around the top bearing.

What is claimed is:  
     
       1. A quill assembly for use in a lawn mower for transferring power from a belt drive connected to a pulley at the top of the assembly to a rotating cutting blade connected at the bottom of the assembly, the quill assembly comprising: 
       a. a housing having a central bore extending from a top of the housing to a bottom of the housing;  
       b. a bottom bearing supported by a seat within a bottom bearing bore at the bottom of the housing;  
       c. a top bearing having an outer ring supported by a seat within a top bearing bore at the top of the housing;  
       d. a jackshaft having a center portion positioned within the central bore of the housing and supported for rotary operation by the top and bottom bearings, a blade end of the jackshaft extending from the bottom of the housing and a pulley end of the jackshaft extending from the top of the housing;  
       e. a pulley adapter adjoining the top of the housing, the pulley adapter having a center section with a central bore positioned around the pulley end of the jackshaft in a slip-fit engagement and an adjacent outer section with a flexible outer lip extending over and sealing the top of the housing, the flexible outer lip being flexible enough to bend when it contacts the housing; and  
       f. a blade adapter recessed into a blade adapter counter-bore at the bottom of the housing, the blade adapter having a central bore surrounding the blade end of the jackshaft.  
     
     
       2. The quill assembly of  claim 1  wherein the blade adapter counter-bore is larger than the bottom bearing bore such that the blade adapter engages the housing to form a seal for the bottom bearing. 
     
     
       3. The quill assembly of  claim 1  further comprising an annular groove formed around the housing proximate the top of the housing, the groove receiving the outer lip of the pulley adapter. 
     
     
       4. The quill assembly of  claim 1  wherein the top bearing bore has a diameter sized to define a slip fit engagement between the top bearing and the top bearing bore whereby the top bearing floats within the top bearing bore. 
     
     
       5. The quill assembly of  claim 1  wherein the center portion of the jackshaft has a larger diameter than the blade and pulley ends to form top and bottom shoulders on the jackshaft that support respective inner rings of the top and bottom bearings. 
     
     
       6. The quill assembly of  claim 5  wherein the top and bottom shoulders on the jackshaft are positioned at predefined locations along the jackshaft such that the top and bottom bearings are supported at predefined vertical positions along the jackshaft without the use of separate bearing spacers. 
     
     
       7. The quill assembly of  claim 1  wherein the center section of the pulley adapter Q extends upwardly from the top of the housing to support a pulley at a pre-defined vertical position above the assembly without the use of a separate pulley spacer. 
     
     
       8. The quill assembly of  claim 1  wherein the bottom bearing has an outer diameter forming a press fit engagement between the bottom bearing and the bottom bearing bore. 
     
     
       9. The quill assembly of  claim 1  wherein the central bore of the blade adapter has a diameter forming a press fit engagement with the jackshaft. 
     
     
       10. The quill assembly of  claim 2 , the blade and blade adapter counter-bore defining a labyrinth seal with respect to the bottom end of the housing.